【词汇讲解】
1.optional adj. 任选的
如：It is optional with you.
那是你的自由。
Permitting discretion; optional.
允许自行处理的; 随意的
2.Trim v. 修除，削剪，装备，痛打，击败，使整洁
如：We have to trim our cost if we want to increase our profit.
我们如果想增加利润，就必须削减开支。
I'll have my hair trimmed tomorrow.
明天我要修剪头发。
3.classified adj. 分类的，类别的，被指定为机密的
如：The books in the library are classified by/according to subject.
图书馆的书是按照[根据]科目分类的。
I'm looking for the classified section. Have you seen it?
我正在找分类广告栏，你见到了吗？
4.deduct vt. 扣除
如：The remaining assets of a business after all liabilities have been deducted; net worth.
资产净值一个企业在扣除了所有的债务后所余资产; 净值
Tax is deducted from your salary.
税金从你的薪金中扣除。